Carburetor



M y 1957 u. s. ADAMSON FIG. 6.

CARBURETOR Filed Aug. 2, 1954 5 1 N V EN TOR.

IL! Adaman- FIG. 2.

ATM/WE).

United States Fatent Q CARBURETOR Uvadale Sankey Adamson, San Jose, Calif.

Application August 2, 1954, Serial No. 447,058

3 Claims. (Cl. 48-184) This invention relates to carburetors and deals with a carburetor designed to handle gaseous fuels of all types, but more particularly fuels, such as butane, propane, natural gas, and the like.

The primary object of this invention is to provide a carburetor that will handle fuels for internal combustion engines with a maximum eificiency over a wide range of volume variations.

It is another object of this invention to provide a carburetor wherein quick starting and quick acceleration may be had under all conditions of weather. This is accomplished by causing the gases to meet and impinge at high velocities in an annular zone, thus providing a quick intimate mixture so essential to over all carburetting efi'iciency and particularly to quick starting and quick acceleration. More specifically, it is an object of this invention to introduce the gases to be mixed in the form of thin sleeves which are concentrically arranged to impinge at an angle in an annular area.

A further object is the provision of means in a carburetor wherein the mixing zone is characterized by a large lateral extent with respect to the distance the gases travel to effect a completely intimate mixture.

Still another object is the provision of means whereby the gases to be mixed may be separately metered in predetermined ratios over a wide range of volume flow variations.

A still further object of this invention is the provision of means whereby the ratio between the gases to be mixed may be varied in accordance with predetermined requirements of varying engine speeds.

Other objects and advantages, such as simplicity of design, ease of manufacture, durability, scarity of moving parts, lack of levers and joints, elimination of needle valves, etc., will become apparent as the description proceeds in conjunction with thedrawing in which:

Figure 1 is a sectional view taken on line 1-1 of Figure 4;

Figure 2 is a cross sectional view, taken on line 2-2 of Figure 1;

, Figure 3 is a sectional view taken on line 3-3 of Figure 1;

Figure 4 is an end view taken on line 4-4 of Figure 1;

V Figure 5 is a fragmentary view of part of Figure 1 showing how the parts would look in another position;

Figure 6 is a fragmentary view of Figure 5, taken on line 6-6;

Figure 7 is an end view of Figure 6;

Figure 8 is a fragmentary side elevation of part of Figure 1; and

Figure 9 is a view showing another form part of my invention may take.

1 Referring to the drawing, and particularly to Figure 1, it will be seen that my invention comprises a casing, generally designated A. The casing is divided into chambers 11 and 12, connected by a sloping walled chamber 13. The chamber 11 forms the air inlet to the carburetor, while the chamber 12 may be said to be the mixing chamber. The sloping walled chamber 13, in combination with other means to be described, provides an arrangement, which acts as a metering chamber for controlling the amount of air admitted to the mixing zone.

At the end of the casing opposite the air inlet, I provide a bore 14 centrally of the casing that communicates with the chamber 12, and into this bore, I press fit a tube 15 that extends rigidly into and through the chamber 12. Communicating with the tube 15, is a passage 16 in the thickened portion of the casing which is threaded as shown at 17, to receive a conduit or any other suitable conductor of fuel gas. Similarly, the chamber 12 is provided with a passage 18, having a fiange 19 arranged to connect the output of the passage to an intake manifold of an internal combustion engine.

The only moving parts of my carburetor consist of the metering and mixing units. These are best shown in Figure 1, and comprise a rod 20, mounted axially of the tube 15 for longitudinal movement therein. The rod 20 is supported at one end by a member 21, which acts to guide the rod in the tube and also to seal otf the end of the tube. For convenience, the member 21 is shown as being screw threadedly mounted in the casing, but it may equally as well be mounted in the end of the tube 15, for all practical purposes.

On the inner end of the rod 20, I mount what may be termed, the mixing and metering unit, generally designated B, best shown in Figure 8. The function of this unit will become apparent as its structure and purpose are explained. The primary purpose of this unit, is to meter both the air and gas and to force both of them to take the shape of thin concentric flowing sleeves that impinge in an annular zone.

It will be noted that the rod 20 is screw threaded on the inner end. In assembling this portion of the carburetor, an inner cone 22 is first screwed onto the end of rod 20 and set in position by a lock nut 23. The unit B is then screwed onto the outer end of the rod behind the cone member 22 and locked in place by means of a lock nut 25.

For a more detailed explanation of the construction of the unit B, reference should be had to Figures 1, 5, and 8. Here it can be seen, that the unit B consists of an outer shell 24 mounted on an inner core member, generally designated 26. This may be done by press fitting the shell 24 over the core 26. The member 26 is formed with a bore 27, adapted to slidably fit over the end of the tube 15. The bore is closed at one end to form a chamber to receive the gas as it flows past the venturi arrangement, also to provide screw threads for mounting the unit on the rod 20. The wall of the bore is slotted, as shown at 28, to provide passage for the gas into an annular chamber 29, formed in the unit 13. The chamber 29 opens into chamber 12 through an annular passage 36. It will be noted, that the outer wall of the shell 24 is sloping at its upper end to form a face 31 adjacent the annular opening 30. In practice, there is a fine dividing edge between the opening and the face which forms the point at which the gas and the air meet for the first time. The angle between these two members also becomes important in controlling and regulating the rate and speed of admixing. It will be further observed, that the slope of the face 31 and the slope of the wall 13 are complementary, and by referring to Figure 1, it can be seen, that the face 31 seats against the wall 13 to form a closure against any air being admitted into chamber 12, when the rod 20 is withdrawn into the tube 15. Since this would close off all air passing into the chamber 12' and prevent any mixture being present for idling speed of the engine, I provide flutes 32 in the face 31 which allow a certain amount of air to pass into the mixingchamber 12, even when the air inlet valve is seated and closed. Similarly, I provide flutes 33 in the cone shaped member 22 to permit gas to flow out into chamber 12 to permit suflicient fuel to be present for idling speed regardless of the position of the air inlet valve. The combination of these twomeans, permits an idling adjustment that will be more fully explained.

The means for moving the rod 20, to vary the volume of carburetted fuel supplied to the engine, may take a variety of forms, but I have found in practice, to get the best results, it is necessary to compensate for the vacuum set up by the engine suction, when moving the member B. To accomplish this, I install a diaphragm 34 on the end of the casing opposite the air inlet, and form a cavity 35 on the end of the casing to permit movement of the diaphragm, and attach the diaphragm to the rod 20. The cavity 35 communicates with the chamber 12 through a small passage way 36, so that any change in pressure in the chamber will be reflected in the cavity. Diaphragm 34 is so proportioned that it produces a vacuum balance that compensates for the air intake pressure on the mixing and metering unit B, thus providing for quick easy movement of the unit for speed control. To hold the diaphragm in place, I provide a cover arrangement, generally designated 37, suitably mounted on the end of the casing A and equipped to provide a sliding fit for the rod 20. It is formed with a bleeder hole 38 to permit air to enter and allow an unhampered movement of the rod and the diaphragm. I The means for operating the rod may take any form desired. For illustration, I have shown a lever 39, pivotally mounted on a bracket 40 on the member 37. A tension spring 41 normally holds the rod in a position where the air inlet and the gas are in idling position.

In Fgure 9, I have shown how an important part of my invention may take another form. This part has to do with the gas metering unit. As stated, with respect Figures 1, 5, 6, and 7, the unit 22 acts as a venturi device and meters the gas admitted to the chamber 29 for mixing with air from the chamber 11. Since the ratio of fuel to air has certain points in the speed variation range, where fixed changes should be made, I conceived the idea of changing the contour of the venturi member 22 to meet these changes at predetermined points. In Figure 9, I have shown well defined steps, which will produce abrupt changes in the flow of gas as the venturi meters opens up for speed of the engine. In some cases, it might be advisable to use a smooth curve generated and produced in accordance with an analysis of the changes desired. As shown, the rod 20 carries a cone,

generally designated 42, in identically the same manner as the cone 22 in the other views. In all other respects, with the exception of the changes in the characteristics of member 42, the construction is the same. In this case, the member 42 is formed with annular steps 43 and 44. The purpose of this form is to provide a pronounced change in the fuel-air ratio, upon a short movement of the rod 20. The advantage of the step arrangement resides in the fact that the steps may be put at any point desired on the cone and introduce the changes at predetermined volumes or speeds.

To conform to the standard practice of controlling the spark advance by means of engine manifold pressures, I provide a passage 45 in the casing which extends into and through the wall 13, as shown. The outer end of the passage is threaded to receive a conduit in the usual manner to conduct the pressure variations to the distributor. The inner end opens on the upper part of the wall 13 in such manner that it will be completely closed when the member B is seated on the wall, such as is shown in Figure 1. This would be the idling position of the carburetor. A quick opening of the air inlet by moving the unit B outwardly would give rise to a sudden vacuum in the passage 45 and operate the spark control mechanism in the usual manner.

In operation, the carburetor would be set for idling in the following manner: The unit 22 would be set as shown in Figures 6 and 7. This would allow only a fixed amount of gas, including that passed by the flutes, to fiow into and mingle with the air stream. The unit would then be locked in position by the lock nut 23. The unit B would then be mounted on the end of the rod in like manner, that is, it would be screwed onto the end of the rod until the face 31 seated on the wall 13, whereupon it would be backed off slightly, thus leaving a certain amount of air to pass into the mixing chamber, without disturbing the position of the cone venturi 22. In addition, to the air passed through the seat, additional air would pass through the flutes 32. In practice, the amount of air admitted in this way would be insufiicient to support idling speed. Additional air would then be admitted through a needle valve, generally designated 46 and the proper idling speed and smoothness of the engine could be adjusted in this manner.

For speed changes in the engine, the lever 39 is worked in the direction of the arrow 47 by any conventional means, such as a foot throttle, and the unit B is pushed off the seat on the wall 13, thus admitting air to flow inwardly into the carburetor under suction from the engines As the air flows inwardly past the unit B, it is formed into a thin sleeve and flows over the sloping shoulder of face 31 into direct contact with a similar sleeve flowing outwardly through the annular passage from the gas chamber 29. These two sleeves impinge at an angle, and due to the fact that they are thin sleeves travelling at high velocity, an intimate mixture takes place between the two almost instantly.

It will be noted that the fuel and the air are both subjected to the direct suction of the engine, thereby resulting in an immediate even flow of the predetermined fuel-air ratio throughout the entire range of the carburetor. Also, that the angle of impingement between the two sleeves remains constant for all speeds. Moreover, due to the instant mixing and the even fuel-air ratio, which is maintained at all speeds, a high fuel economy is realized at all speeds, but particularly at partial throttle speeds.

I claim:

1. A carburetor comprising; a casing; said casing having a mixing chamber theerin, a gaseous fuel inlet tube axially mounted within said casing, a rod mounted in said tube for longitudinal movement therein, a first member on said rod for metering gas from the end of said tube, a second member on said rod arranged to meter air in an annular form into said mixing zone, said second member having a chamber therein arranged to receive gas from said first member, and said chamber having an annular outlet arranged to discharge gas concurrently with said air stream into said mixing zone in an annular form closely adjacent to and concentric with said annular air form.

2. The elements of claim 1 and in addition thereto; means for moving said rod to operate said members simultaneously.

3. The elements of claim 2 and in addition thereto; a diaphragm mounted in a closed chamber on the end of said casing connected to said rod to exert a control there- :on proportional to pressure in said chamber, there being a passage communicating said chamber with said mixing chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,013,214 Noyes Jan. 2, 1912 1,174,003 Gibson Feb. 29, 1916 1,535,702 Walsh et al. Apr. 28, 1925 1,563,246 Zulver Nov. 25, 1925 1,802,019 Howson Apr. 21, 1931 1,806,790 Dasey May 26, 1931 2,366,322 Foster Jan. 2, 1945 'w an 

1. A CARBURETOR COMPRISING; A CASING; SAID CASING HAVING A MIXING CHAMBER THEREIN, A GASEOUS FUEL INLET TUBE AXIALLY MOUNTED WITHIN SAID CASING, A ROD MOUNTED IN SAID TUBE FOR LONGITUDINAL MOVEMENT THEREIN, A FIRST MEMBER OF SAID ROD FOR METERING GAS FROM THE END OF SAID TUBE, A SECOND MEMBER ON SAID ROD ARRANGED TO METER AIR IN AN ANNULAR FORM INTO SAID MIXING ZONE, SAID SECOND MEMBER HAVING A CHAMBER THEREIN ARRANGED TO RECEIVE GAS FROM SAID FIRST MEMBER, AND SAID CHAMBER HAVING AN ANNULAR OUTLET ARRANGED TO DISCHARGE GAS CONCURRENTLY WITH SAID AIR STREAM INTO SAID MIXING ZONE IN AN ANNULAR FORM CLOSELY ADJACENT TO AND CONCENTRIC WITH SAID ANNULAR AIR FORM. 